Re: [PATCH] SUNRPC: Fix iter_iov_*vec warnings
From: Trond Myklebust
Date: Mon Oct 29 2018 - 14:02:39 EST
Cc: Al, since this wants to go through his pull request (the RPC code
has already been merged).
On Mon, 2018-10-29 at 17:55 +0000, Julien Thierry wrote:
> While booting linux-next on Juno with rootfs over NFS, the following
> warning is spammed on kernel log:
>
> [ 16.988190] WARNING: CPU: 1 PID: 680 at lib/iov_iter.c:1082
> iov_iter_kvec+0x20/0x40
> [ 16.995776] Modules linked in:
> [ 16.998801] CPU: 1 PID: 680 Comm: kworker/u13:0 Not tainted
> 4.19.0-next-20181029 #2238
> [ 17.006640] Hardware name: ARM Juno development board (r0) (DT)
> [ 17.012505] Workqueue: xprtiod xs_stream_data_receive_workfn
> [ 17.018108] pstate: 00000005 (nzcv daif -PAN -UAO)
> [ 17.022851] pc : iov_iter_kvec+0x20/0x40
> [ 17.026733] lr : xs_stream_data_receive+0x194/0x378
> [ 17.031559] sp : ffff00000b033ce0
> [ 17.034836] x29: ffff00000b033ce0 x28: 0000000000000000
> [ 17.040095] x27: ffff8009760b9870 x26: ffff00000917e1c8
> [ 17.045352] x25: 0000000000000000 x24: ffff800976a91598
> [ 17.050610] x23: ffff000009169000 x22: ffff8009775f0000
> [ 17.055867] x21: 000000000000000c x20: ffff800976a91578
> [ 17.061124] x19: ffff800976a91000 x18: 0000000000000000
> [ 17.066381] x17: 0000000000000000 x16: 0000000000000000
> [ 17.071639] x15: 0000000000000400 x14: 0000000000000400
> [ 17.076896] x13: 0000000000000400 x12: 0000000000002f28
> [ 17.082153] x11: 0000000000000000 x10: 0000000000000960
> [ 17.087410] x9 : ffff00000b033d50 x8 : fefefefefefefeff
> [ 17.092667] x7 : ffff80097ff9d380 x6 : 0000000000000000
> [ 17.097924] x5 : 00646f6974727078 x4 : 000000000000000c
> [ 17.103181] x3 : 0000000000000001 x2 : ffff00000b033d30
> [ 17.108438] x1 : 0000000000000002 x0 : ffff00000b033d50
> [ 17.113695] Call trace:
> [ 17.116115] iov_iter_kvec+0x20/0x40
> [ 17.119652] xs_stream_data_receive_workfn+0x10/0x18
> [ 17.124568] process_one_work+0x1c8/0x318
> [ 17.128535] worker_thread+0x48/0x428
> [ 17.132158] kthread+0xf8/0x128
> [ 17.135266] ret_from_fork+0x10/0x18
> [ 17.138801] ---[ end trace 65cbcd2ddaeef59e ]---
>
> This is likely a clash between the recent addition of vector
> iterators to
> SUNRPC and the recent
> commit aa563d7bca6e882ec2bdae24603c8f016401a144 ("iov_iter: Separate
> type from direction and use accessor functions") which slightly
> changes
> the usage of those iterators by splitting type and direction.
>
> Fix this by not including type in the direction of the operation.
>
> Fixes: 277e4ab7d530bf287e02b65cfcd3ea8f489784f6 ("SUNRPC: Simplify
> TCP
> receive code by switching to using iterators")
>
> Signed-off-by: Julien Thierry <julien.thierry@xxxxxxx>
> Cc: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
> Cc: Anna Schumaker <anna.schumaker@xxxxxxxxxx>
> Cc: "J. Bruce Fields" <bfields@xxxxxxxxxxxx>
> Cc: Jeff Layton <jlayton@xxxxxxxxxx>
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Cc: netdev@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> ---
> net/sunrpc/xprtsock.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
> index 1b51e04..ae77c71 100644
> --- a/net/sunrpc/xprtsock.c
> +++ b/net/sunrpc/xprtsock.c
> @@ -361,7 +361,7 @@ static void xs_free_peer_addresses(struct
> rpc_xprt *xprt)
> xs_read_kvec(struct socket *sock, struct msghdr *msg, int flags,
> struct kvec *kvec, size_t count, size_t seek)
> {
> - iov_iter_kvec(&msg->msg_iter, READ | ITER_KVEC, kvec, 1,
> count);
> + iov_iter_kvec(&msg->msg_iter, READ, kvec, 1, count);
> return xs_sock_recvmsg(sock, msg, flags, seek);
> }
>
> @@ -370,7 +370,7 @@ static void xs_free_peer_addresses(struct
> rpc_xprt *xprt)
> struct bio_vec *bvec, unsigned long nr, size_t count,
> size_t seek)
> {
> - iov_iter_bvec(&msg->msg_iter, READ | ITER_BVEC, bvec, nr,
> count);
> + iov_iter_bvec(&msg->msg_iter, READ, bvec, nr, count);
> return xs_sock_recvmsg(sock, msg, flags, seek);
> }
>
--
Trond Myklebust
CTO, Hammerspace Inc
4300 El Camino Real, Suite 105
Los Altos, CA 94022
www.hammer.space